1. Field of the Invention
The present invention relates to starting elements or starting converters, particularly a starting element comprising a hydrodynamic torque converter.
2. Description of the Related Art
Starting elements for transmitting a torque from a drive unit to a downstream drivetrain, for example, a transmission, are known in a variety of embodiments. Hydrodynamic converters or hydrodynamic torque converters which are mechanically locked up to increase energy efficiency after starting in the so-called lockup mode of converter lockup clutches so as to prevent flow losses and to optimize consumption of fuel or driving energy are often used to enable automatic starting. Starting elements or starting converters of this kind are often combined with so-called torsional vibration dampers which can comprise one or more stages and which have a drive-side input component part that can be connected to a rotating drive unit so as to be fixed with respect to rotation relative to it. Located between this input component part and a driven-side output component part are one or more energy accumulators or damper elements, for example, in the form of coil springs, which can serve to suppress vibrations in the drivetrain in lockup mode. Accordingly, the torque is transmitted from the input component part of the torsional vibration damper, via the energy-accumulating or vibration-damping elements, to the output component part which is connected to the output of the starting element so as to be fixed with respect to rotation relative to it. In general, by drive-side component is meant hereinafter a component or assembly which, with respect to the flow of force from the driving unit to the end of the drivetrain, is located closer to the driving unit than a component designated as being on the driven side.
Further, so-called tuned mass dampers are also installed in order to further increase driving comfort and to further suppress vibrations in the drivetrain with locked up converter. Tuned mass dampers are, generally speaking, added mass linked to the drive system or torsional vibration damper by a suspension system. For example, a tuned mass damper operates on the principle that a vibratory system comprising a main mass and an auxiliary mass is so tuned with respect to its natural frequency that at a certain excitation frequency the auxiliary mass, referred to hereinafter as damper weight, carries out a forced vibration, while the main mass remains at rest so that vibration frequencies of this kind can be efficiently suppressed.
To achieve the suppression of vibrations over a larger range of rotational speeds, speed-adaptive mass dampers are used whose natural frequency or resonant frequency changes as a function of rotational speed, for example, proportional to the rotational speed. Thus by tuned mass damper is meant herein a device or mechanism or arrangement of components by which no torque is transmitted and which is capable of removing energy from the drivetrain at a determined, possibly variable, vibration frequency in order to suppress torsional vibrations occurring at this frequency.
Arranging a plurality of such components or assemblies in a starting element in an efficient and space-saving manner represents a substantial challenge.